Clipper



I. O. MINER Jan. 24, 1933.

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M flaw @Iz 2 Sheets-Sheet 2 l. O. MINER CLIPPER Filed April 24. 1931Jan. 24, 1933.

,ZMQXZZQ 5 a 4M Mamba ym v Patented Jan. 24, 1933 UNITED STATES PATENTOFFICE IRVING O. MINER, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO BROWN &SHARPE MANUFACTURING COMPANY, A CORPORATION OF RHODE ISLAND CLIPPERApplication filed April 24,

The invention relates to a clipper, and more particularly to a hairclipper in which one blade is given a vibratory movement rela tively toa stationary blade to produce a substantially continuous cutting actionof the two blades.

In a clipper of this description which may be driven automatically at ahigh rate of speed by some form of electric motor, as for instance,where the impulses impressed on an electromagnet by an alternatingcurrent are utilized to secure a rapid oscillation of a spring-pressedarmature relative thereto, the vibratory movements of the moving bladeand the driving connections therefor tend to set up a correspondingvibration of the casing which has been found to be extremelyobjectionable.

It is one object of the present invention to eliminate this vibration ofthe clipper casing or support induced by the vibratory movements of themoving parts, and thus to provide a clipper which will be moresatisfactory and successful for practical use than those previouslyproduced.

It is of the utmost importance in a vibratory hair clipper of thegeneral type herein disclosed, in order to secure its satisfactoryoperation under the vva-ryin conditionsof commercial use, that a stab econdition be maintained at all times in the adjustment of thenaturalperiod and amplitude ofvibration of the vibrating system,consisting of the movable blade, the armature and the tuning springs,with relation to the frequency of the driving impulses of thealternating current. Inasmuch as the tuning of the system must depend onthe strength of the tuning springs with relation to the weight or massotthe elements controlled thereby, it is necessary in adjusting thetuning of the vibrating system to take into consideration tlfe'tveightand tendency to vibrate of the casing or handle of the clipper. Fromactual use, it has been demonstrated that this adjustment in the tuningof the clipperis considerably affected by the grip of the operator andby the contact of the stationary clipper blade with the surface againstwhich the clipper is operating. Where the operating conditions are suchas to 1931. Serial No. 532,458.

substantially overcome and damp out the vi bration of the casing, theadjustment of the tuning of the system with relation to the impressedvibrations of the alternating current is in many instances so changed asto render the device inoperative.

It is therefore more specifically one object of the present invention toprovide a cli per of the general type herein disclosed in w ich thetendency of the clipper casing to vibrate at the frequency impressed bythe driving impulses of the alternating current is completely overcomeunder all operating conditions to maintain a stable adjustment of thenatural period and amplitude of vibration of the moving parts.

It is another object of the present invention to provide a novel andimproved clipper which will be quiet in operation as compared withclippers previously produced, and will be so arranged as to permit thewear on the parts through continued operation to be taken up withoutinterfering with the quiet or efficient operation of the device.

With these objects in view, one feature of the invention consists in theprovision of a dynamic vibration absorber which is arranged to offsetthe vibratory movement of the moving parts of the clipper, and therebydamp out the vibrations set up in the casing.

Another feature of the invention consists in the. arrangement of thearmature and movable blade and of the springs for controlling theoperation of these parts to maintain at all times a quiet and efficientoperation of the clipper.

The several features of the invention consists also in the devices,combinations, and arrangement of parts hereinafter described .andclaimed which. together with the advantages to be obtained thereby, willbe readily understood by one skilled in the art from the followingdescription taken in connection with the accompanying drawings, in whichFig. 1 is a plan viewot the clipper with the cover removed; Fig. 2 isaside view taken substantially on the line 22 of Fig. 1; Fig. 3 is adetail sectional view taken substantially on the'line 33 of Fig. 1,showing particularly the two clipper blades and certain of 100 theiroperating connections; Fig. 4 is a sectional view taken on line 44 ofFig. 1; Fig. 5 is a detail plan view of the dynamic vibration absorber;and Fig. 6 is a side view of the same.

The hair clipper disclosed in the drawings as embodying in a preferredform the several features of the present invention comprises a casing 8which houses the operating parts of the clipper and also forms a handlewhich may be conveniently grasped by the hand of the operator. At theforward end of the casing, a fixed cutter blade 10 is secured by meansof the clamping screws 12, as indicated in Fig. 2. Cooperating with thefixed blade 10 is a movable blade 14 which is arranged to move laterallyof the fixed blade being guided in this path by engagement of two barsor keys 16 in a corresponding slot 18 formed in the fixed blade 10. Thebars 16 are secured to move with the movable blade 14 by means of screws20.

The power for operating the clipper is supplied by means of anelectromagnet to which driving impulses are imparted at a rapidfrequency by an alternating electric current to secure a rapid vibratorymovement of'an armature 26 which is arranged to oscillate the movableblade 14. The current is applied to the electromagnet comprising a core22, roughly U shaped, and provided on one arm of the U with a winding24, through electrical connections which include a cable 28 which entersthe casing through a nut 30 provided for this purpose at the rear of theclipper, and a starting and stop ping switch indicated generally at 32.

e armature 26 intermediate its length is mounted on a spring 34 whichserves as a ivot about,which the armature can swing. or convenience inconstruction, the armature is built up of two separate members which areriveted to the spring 34 and to each other, the rear member or armatureproper comprising a flat bar arranged on edge to cooperate directly withpoles of the electromagnet, and the forwardly extending tongue arrangedin a flat or horizontal position shaped at its forward end to engagewith a corresponding slot 38 in the movable blade 14. As will be notedfrom Fig. 1 of the drawings, the slot 38 is wider than the engagingrtion of the tongue 36.

In or er to provide a satisfactory operating connection between theclipper blade- 14 which, as above pointed out, has a straight linemovement with relation to the fixed blade 10 and the engaging portion ofthe tongue 36 of the armature which has an arcuate movement about itspivoting spring, one feature of the present invention contemplates anarrangement of the cutter return and tension springs and the adjustingspring for the vibratin armature and the movable blade, which Wlll causethe tongue 36 to be held at all times in contact with one side of theslot 38. To this end, spring means are provided which tend to move theblade 14 and the armature tongue at all times in o posite directions,the relative strength of the springs being at the same time so adjustedwith relation to each other and to the weight of the moving parts as tosecure the required amplitude and natural period of vibration of thewhole system with relation to the impressed period of vibration of thealternating current circuit. Acting directly on the movable blade 14 aretwo main cutter return and tension springs 40 which engage in recesses42 in the upper surface of the blade and tend to hold it at the extremelimit of its movement in a direction opposed to the direction of thepull exerted by the electromagnet through the armature on the movableblade. These springs are secured to a block 44 which is in turn mountedon a flat spring member 46 secured by a nut 48 to the casing 8. Thesprings arranged in this manner are made to serve two separatefunctions, since they tend to hold the movable cutter blade at the limitof its movement in one direction, and at the same time exert a pressureon the upper face of the cutter blade 14 to hold the two blades incontact. The mounting of the cutter return and tension springs 40 andblock 44 on the flat spring 46 has the effect of giving the springs agreater flexibility in a vertical direction to make possible a moreaccurate adjustment of the bearing pressure of the springs on themovable cutter blade 14 to establish the required frictional contactbetween the blades.

In order to provide an adjustment of the armature to regulate the airgap between the armature and the electromagnet, and also to providemeans for holding the armature at all times in contact with a side ofthe slot 38, a compression spring 50 is seated in a hollow nut 52screw-threaded into the side of the casing, and bears against thearmature at a point adjacent to its pivotal connection with the spring34 tending to move the armature toward the poles of the electromagnetagainst the'action of the springs 40.

With this arrangement of the cutter return and tension springs 40 andthe spring 50, a oint of contact is maintained at all times tween themovable blade and the armature which eti'ectually prevents anyundesirable play between the parts, with consequent noise or chatter inthe connection, and further compensates automatically for wear on thebearing surfaces with continued With the construction of the clipperherein disclosed in which the movable blade is arranged to reciprocatein a path determintd by engagement of the keys 16 with the guideway 18,ditiiculty has been experienced in preventing undesirable back lashbetween the keys and the guideway as the movable blade is propelledfirst in one direction and then in the ot er by the armature tongues 36and the return springs 40. To overcome this difiiculty, the tongue 36 ofthe armature and the return springs 40 are arranged to engage with themovable blade 14 at points on different planes parallel to the line ofmovement of the blade 14, so that the opposed forces of the returnsprings 40 and the armature tongue 36 will tend at all times to exert atwisting strain on the movable blade with relation to the guideway 18 tohold the upper or left hand key 16 as shown in Fig. 1 in contact 15 withthe rear side of the guideway and the lower or right hand key 16 inengagement with the rear side of the guideway.

In order to prevent any disarrangement of the coils of the spring 50 asthe nut 52 is turned up or backed off to vary the load on the armature,the base end of the spring is bent inwardly and down to provide acentrally located pivot 54 which engages in a corresponding indentationin the nut, and permits the rotation of the nut without changing thepositions of the coils of the spring. To assist in the tuning of thevibrating system which includes the springs above enumerated, themovable blade and the armature, with relation to the impressed impulsesof the alternating current, a weight 55 is socured by means of a screw56 to the forward end of the armature tongue 36.

In order to eliminate objectionable vibration of the clipper casing andto provide a clipper which will operate smoothly and evenly, a dynamicvibration absorber is provided which acts automatically to damp out anytendency of the clipper casing to vibrate caused by the vibratorymovements of the armature and movable blade. This absorber unitcomprises a spring member 60 formed integrally with a plate 62 which isrigidly secured by a screw 64 and pins 66 to the clipper casing. At itsfree end, the spring member 60 carries a weight 68 which is adjustedrelatively to the strength of the spring 60 to impart to the vibrationabsorber a natural period of vibration which will be equal to the periodof vibration set up in the casing by the moving parts of the clipper.The vibration of the casing will then tend to set up a correspondingvibration of the vibration absorber unit which will be 180 out of phasewith the vibrations of the casing and of a corresponding intensity oramplitude to sub stantially damp out the vibrations of the cas- In aclipper of the type herein disclosed which is operated by an alternatingelectric current, the rate of vibration of the moving parts of theclipper and the consequent rate of vibration set 11 in the casing isdetermined solely by the fiequency of the driving impulses impressed onthe armature by the alternating electric current, and is in no waydependent on the tuning of the natural period of vibration of thevibrating system. Since the frequency of the electric current remainsconstant and must therefore maintain constant the frequency of thevibratory movements of the armature and movable blade, the dynamicvibration absorber when once tuned to damp out corresponding vibrationsset up in the casing at this frequency, will be effective to eliminatethe vibration of the casing under all possible 0 crating conditions.Changes in the amplitu e of the vibrations which tend to be set up inthe clipper casing, and any changes which may occur in the effectiveweight of the vibrating mass, due to alteratiOns in the operatingconditions under which the clipper is used, are automatically taken careof by the vibration absorber unit which tends to have a correspondinglgreater or less amplitude of vibration to 0 set the force of thevibrations set up in the casing.

In clippers of the vibratory type, as heretofore constructed, in whichno provision has been made for damping out the counter vibrations set upin the clipper casing, the adjustment of the amplitude and naturalperiod of vibration of the vibratory system with relation to the periodof vibration impressed on the armature and movable blade by the drivingimpulses of the alternating current is necessarily dependent to aconsiderable extent on the weight and tendency to vibrate of the clippercasing itself, since the characteristics of any vibratory system aredependent on the relative values of the strength of the springs and theweight or mass of the moving parts. Under these conditions, it will beevident that where for any reason during the operation of the clipper,the casing is partially or wholly prevented from vibrating, the strengthof the springs will be substantially increased with relation to the massof the moving parts, and will result in a material change in the tuningof the system and also in the amplitude of movement of the armature andmovable blade.

It has been found by actual experience that the damping effects producedon the vibration of the clipper casing to a greater or less extent bythe grip of the operator and by contact of the stationary blade with anystationary object will upset the adjustment and tuning of the naturalperiod of vibration of the vibrating system with relation to thefrequency impressed by the alternating current to such an extent as toresult in the faulty operation of the clipper, and in some instances,even to render it entirely inoperative.

From the above discussion, it will be seen that the provision of meansfor damping out at all times the counter vibrations set up in theclipper casing by the vibratory movements of the armature and movableblade will have the effect of preventing any change in the tuning of thesystem and the consequent faulty operation of the clipper, due to thetendency of other objects brought 1n contact with the casing during theoperation to produce a damping eifect on these vibrations to a greateror less degree. The introduction of the dynamic vibration absorber 1nthe construction herein disclosed to eliminate these vibrations of theclipper casing therefore has an important advanta e in preventing anychange in'the tuning o the system under the varying conditions ofcommercial use, and results inthe production of a clipper which is moresatisfactory and efiicient In operation than any clipper previouslyproduced.

While the several features of the invention have been herein disclosedin their preferred form in a hair clipper particularly adapted fortonsorial use, and is of the vibratory type in which the impulsesimpressed upon an electromagnet by an alternating current are utilizedto impart a rapid vibratory movement to a tuned vibratory systemincluding a movable blade and armature and tunlng springs, it will beunderstood that certain features of the invention are not to be limitedto this specific type of clipper, but may be equally applicable toclippers of other types and for different uses.

Having thus described the invention, what is claimed is:

1. In a clipper, the combination with a casing, of a stationary clipperblade carried by the casing, a movable clipper blade cooperating withthe stationary blade, means carried by the casing for impartingvibratory movements to the movable blade, and a dynamic vibrationabsorber actuated only by vibrations tending to be set up in the casingand comprising a weighted spring member having a natural period 0oscillation corresponding to that impressed on the clipper by thevibrato movements of the movable blade and said actuating means andrigidly secured to the casing at a point to substantially eliminate saidvibrations.

2. In a clipper, the combination with a casing, of a stationary clipperblade carrled by the casing, a movable clipper blade cooperating withthe stationary blade, means carried by the casing for impartingvibratory movements to the movable blade, and a dynamic vibrationabsorber actuated only by vibrations tending to be set up in the casingand comprising a weighted spring member rigidly secured to the casingand tuned to the period of vibration set up in the casing by theoperation of the clipper.

3. In a clipper, the combination with a casing shaped to be grasped bythe hand of an operator, of a blade carried by the casing, a movableblade cooperating with the stationary blade, means carried by the casingfor imparting vibratory movements to the movable blade at asubstantially constant rate, and a dynamic vibration absorber actuatedonly by vibrations tending to be set up in the easing and comprising aweighted spring member rigidly secured to the casing tuned to thefrequency of the vibration set up in the casin by the operation of theclipper and arrange to permit a variation in the amplitude ofoscillation of said spring member to offset and thereby to eliminatesaid vibrations as modified by contact of the clipper with externalobjects.

4. In a clipper, the combination with a casing, of a stationary clipperblade carried by the casing, a movable clipper blade cooperatingtherewith, an electromagnet, an armature connected to the movable bladeand having a movement toward and away from the poles of the magnet, anda dynamic vibration absorber actuated only by vibrations tending to beset up in the casing and comprising a weighted spring member having anatural period of oscillation corresponding to that impressed on saidmovable blade and rigidly secured to the casing at a point to eliminatevibration of the casing.

5. In a clipper, the combination with a casing, of a stationary clipperblade carried by the casing, a movable clipper blade cooperatingtherewith, an electromagnet, an armature connected to the movable bladeand having a movement toward and away from the poles of the magnet,spring means tending to move the armature away from the poles of themagnet, and a dynamic vibration absorber actuated only by vibrationstending to be set up in the casing and comprising a weighted springmember rigidly secured to the casing tuned to vibrate when renderedoperative by vibrations set up in the casing 180 out of phase with thevibrations of the armature impressed thereon by the pulsations of theactuating current and therebv to substantially damp out said vibrationswhich tend to be set up in the casing.

6. In a clipper, the combination with a casing, of a movable blade, ablade cooperating therewith, an electromagnet, an armature connected tothe movable blade and mounted for movement toward and away from thepoles of the magnet to oscillate the movable blade, a spring memberengaging with the movable blade to resist the pull of the electromagnetand to tension the blades, a block to which said spring member issecured, and a flat spring carrying said block and fastened to thecasing arranged to provide a substantially increased resiliency of thespring system to hold the blades in contact without substantiallyaltering the strength of the spring member exerted laterally to resistthe pull of the electromagnet.

7. In a clipper, the combination with a casing, of a movable blade, ablade cooperating therewith, an electromagnet, an armature connected tothe movable blade and mounted for movement toward and away from thepoles of the magnet to oscillate the movable blade, a pair of springfingers engaging with the movable blade to resist the pull of theelectromagnet and to tension the blades, a block to which said fingersare secured, and a yielding support for said block comprising a fiatspring disposed in the clipper casing in a plane parallel to the line ofmovement of the movable blade, and secured at its forward end to thecasing and at its rear end to the block.

8. In a clipper, the combination with a casing, of a movable blade, ablade cooperating therewith, an electromagnet, an armature connected tothe movable blade and mounted for movement toward and away from thepoles of the magnet to oscillate the movable blade, a spring memberengaging with the movable blade to resist the pull of the electromagnetand to tension the blades, and a yielding support for said spring membercomprising a flat spring disposed in the clipper casing in a planeparallel to the line of movement of the movable blade and secured at itsforward end to the casing and at its rear end to the rear end of thespring member.

9. In a clipper, the combination with a casing, of a stationary clipperblade carried by the casing, a movable clipper blade cooperating withthe stationary blade, a guideway for controlling the direction ofmovement of the movable blade with relation to the stationary blade, anelectromagnet, an armature having a movement toward and away from thepoles of the magnet and arranged for engaging contact with the movableblade, a spring engaging the armature tending to move the armature andmovable blade contacting therewith in the direction of pull of theelectromagnet, and a spring member engaging the movable blade tending atall times to force the blade and the armature having engaging contacttherewith toward the limit of their movement in an opposite directionagainst the pressure of the armature spring, the points of engagingcontact of the return spring and the armature with the movable bladebeing arranged to lie in different planes parallel to the line ofmovement of the movable blade.

10. In a clipper, the combination with a casing, of a stationary clipperblade carried by the casing, a movable clipper blade cooperating withthe stationary blade, a guide- ,way for controlling the direction ofmovement of the movable blade with relation to the stationary blade, anelectromagnet, an armature having a movement toward and away from thepoles of the ma net and arranged for engaging contact with the movableblade, a spring engaging the armature tending to move the armature andmovable blade contacting therewith in the direction of pull of theelectromagnet, and a spring member engaging the movable blade tending atall times to force the blade and the armature toward the limit of theirmovements in a direction contrary to the pull of the electromagnet, theparts being arranged to cause the opposed forces of the armature springand return spring to exert a twisting strain on the movable blade withrelation to the guideway at all times in one direction.

11. In a clipper, the combination with a casing, of a stationary clipperblade carried by the casing, a movable clipper blade cooperatingtherewith, an abutment on the movable blade, an electro-magnet, anarmature having a movement toward and away from the poles of the magnetand arran ed to engage an abutment on the movable c ipper blade, aspring engaging the armature tending to move the armature toward thepoles of the magnet, and spring means mounted on the casing and engagingthe movable blade to force said blade and armature engaging saidabutment to the limit of their movement in an opposite direction againstthe pressure of the armature spring to maintain the movable blade andabutment thereon continuously in engaging contact with the armature.

12. In a clipper, the combination with a casing, of a stationary clipperblade carried by the casing, a movable clipper blade cooperatingtherewith, an abutment on the movable blade, an electro-magnet, anarmature having a movement toward and away from the poles of the magnetand arranged to engage the abutment on the movable clipper blade, aspring engaging the armature tending to move the armature toward thepoles of the magnet, and a unitary spring member mounted on the casingand en aging the movable blade to tension the blades and tending toforce said movable blade and the armature having engaging contact withsaid abutment to the limit of their movement in an opposite directionagainst the pressure of the armature spring to maintain the said bladeand abutment mounted thereon continuously in engaging contact with thearmature.

In testimony whereof I have signed my name to this specification.

IRVING O. MINER.

